Split pins - dull question

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It seems there are two common ways to hold in clevis pins, using split pins or using split rings (the ones where one of the ends of the wire bends through a right angle and points into the centre of the ring).

My understanding is that splin pins should only be used once, but split rings can be re-used. Are split rings just as safe and strong as split pins? Should they be reused in really critical situations, ie where the structure of the boat is dependant on the clevis pin staying in place?

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[vyv_cox]

Re: Split pins - dull answer

Split pins are made from soft metal. Bending them to hold them in place hardens them and can sometimes crack them, although I confess that I have re-used them many times.

Split rings are made from cold extruded wire, which hardens them. Their big disadvantage is that the bent end catches in ropes, clothes and whatever else comes near them. This usually pulls them nearly straight which, due to their material, cannot be corrected. I only use them on clevis pins holding blocks, or similar duties where they are unlikely to catch anything. Anywhere critical, like shrouds, sheet blocks, sheave axles, I use split pins.

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[tcm]

um. IMHO this is at the slightly bodgy or at least non-precision end of the engineering spectrum, so there's less "right or wrong" but depends on the application. I would say that the split pin is used in general applications, but a ring where undoing/redoing is likely to be more frequent, but there are split half-rings and split 1½ rings. What's the application?

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[Guest]

Re: Split pins - dull answer

Having had to resort to split-rings to 'repair' items that have lost / shed split-pins ....... I now use them in most applications instead of pins.
The adage of catching itesm with the rings ..... I find is less with rings than with the sharp 'ends' of pins. All my turnbuckles / bottle-screws use 'em, my engine throttle lever uses 'em ..... in fact as said I use rings in preference - but they MUST be non-corrosive versions. I aslso make sure that the ring is suitable size and not over-size - which can lead to catching etc. in lines etc.

As to the question ...... a ring is designed for allowing release of the item and refastening. A pin is not, its a single use item - as already explained by another.


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I only came - cos they said there was FREE Guinness !

 

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The applications are on my Dragonfly trimaran. This disassembles to go on its trailer for towing, and many of the joints are clevis pins which at the moment are secured by split pins. If I am dismantling and reassembling to take the boat to new waters by road, even only occasionally, there are many split pins that need to be replaced, and they are not cheap.

Some of the applications are even more critical than holding the mast up. For example there are 4 large diameter water stays, which go between the floats and the main hull, held in place by clevis/split pin arrangement. These counteract the heeling force from the mast. If one of these stays was to let go under load, the boat would collapse and capsize. Other applications are the more usual shroud/stay joints.

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[vyv_cox]

When we raced small catamarans, attending many regattas all around UK and Europe, we had loading and unloading down to a fine art. The aim is to minimise the number of pins that have to be removed, so for example we never disconnected shrouds, just left them attached and coiled them on the trampoline. For the few pins that we had to remove I bought some clever devices that are a hollow clevis pin with a spring-loaded plunger operated by a button on one end that releases a small ball at the other. Once the ball is released it allows the clevis pin to be removed. Not very cheap, of course, but over the years these things saved us hours of assembly and disassembly.

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